1. Field of the Invention
The present invention relates to an image signal correction device by which an image signal, obtained by an imaging device, is subjected to a shading correction and a defect correction.
2. Description of the Related Art
Conventionally, in an electronic still camera, each pixel data, corresponding to a part of an image formed on an imaging device, such as a solid-state imaging device, needs to be subjected to a shading correction and a defect correction. The shading correction is carried out for correcting a shade (or a darkness) generated around the periphery of the image, due to the inherent characteristics of an optical element, such as a lens. The defect correction is performed in order to eliminate an effect of a defective pixel (i.e. a defective photo-diode), existing in the imaging device. Thus, the correction device provided in the electronic still camera is provided with a first memory, in which a defect pixel data, such as an address and a flag, indicating a defect pixel position, is stored for each pixel, and a second memory, in which a shading correction data, indicating a correction ratio of the shading, is stored for each pixel.
As described above, in the conventional correction device, since the defect pixel data and the shading correction data are stored in separate memories, each of the memories requires a relatively large capacity.